1. Field of the Invention
The present invention relates to a mobile communications system and, particularly, to a broadcast system and method in the mobile communications system.
2. Description of the Prior Art
There have been proposed several broadcast systems using a mobile communications network including a plurality of base stations each forming a radio communication zone.
In a system disclosed in Japanese Patent Application Laid-Open No. 3-247029, a single radio communication zone is formed by a plurality of base stations, where a specific radio channel is assigned to a selected one of the base stations. When the selected base station receives a broadcast request signal from a mobile terminal, all or predetermined base stations are used to perform broadcasting.
In a broadcast system disclosed in Japanese Patent Application Laid-Open No. 63-52526, when receiving a broadcast request signal from a mobile terminal, a switching system transmits a broadcast mode switch request signal to the mobile terminal. When receiving the broadcast mode switch request signal, the mobile terminal changes a receive channel to the broadcast channel.
However, according to the above conventional system forming a single radio communication zone by using a plurality of base stations, it is necessary to assign the specific radio channel to the selected base station.
Further, according to the above conventional systems, it is impossible to provide broadcast services within only an area smaller than a radio communication zone or cell.